I am new to rc flying and have a park flyer which has a 1 cell 120 mah lipo. It was a rtf so it has its own charger and I have recently bought a 150 mah to fly longer than a few minutes. Iam not sure what the connector is called (the part that plugs in to the charger or plane) but after a few poor landings and recharges this connector on both batteries has become loose in the sence that i can move it back and forth with some ease. I unfortunately had to give both batteries some gental persuation to even get them to fit in the charger since the batteries appeared to not be constructed as perfectly as the charger would have liked. Can I still trust these or do I need to junk them?